Prohibite changing transiency of keys

embedded/store/immustore.go

@@ -61,6 +61,7 @@ var ErrMaxKeyLenExceeded = errors.New("max key length exceeded")
 var ErrMaxValueLenExceeded = errors.New("max value length exceeded")
 var ErrPreconditionFailed = errors.New("precondition failed")
 var ErrDuplicatedKey = errors.New("duplicated key")
+var ErrCannotUpdateKeyTransiency = errors.New("cannot change a non-transient key to transient or vice versa")
 var ErrMaxActiveTransactionsLimitExceeded = errors.New("max active transactions limit exceeded")
 var ErrMVCCReadSetLimitExceeded = errors.New("MVCC read-set limit exceeded")
 var ErrMaxConcurrencyLimitExceeded = errors.New("max concurrency limit exceeded")

embedded/store/ongoing_tx.go

@@ -262,11 +262,17 @@ func (tx *OngoingTx) set(key []byte, md *KVMetadata, value []byte, hashValue [sh
 
 	kid := sha256.Sum256(key)
 	keyRef, isKeyUpdate := tx.entriesByKey[kid]
-
 	if !isKeyUpdate && len(tx.entries) > tx.st.maxTxEntries {
 		return ErrMaxTxEntriesLimitExceeded
 	}
 
+	_, wasTransient := tx.transientEntries[keyRef]
+	if isKeyUpdate {
+		if wasTransient != isTransient {
+			return ErrCannotUpdateKeyTransiency
+		}
+	}
+
 	e := &EntrySpec{
 		Key:              key,
 		Metadata:         md,
@@ -343,7 +349,6 @@ func (tx *OngoingTx) set(key []byte, md *KVMetadata, value []byte, hashValue [sh
 			tx.entries[keyRef] = e
 		}
 	} else {
-
 		if isTransient {
 			tx.transientEntries[len(tx.entriesByKey)] = e
 			tx.entriesByKey[kid] = len(tx.entriesByKey)